1. a summary for A Level Biology
Biodiversity
a summary for A Level Biology

2. Classification of the domestic cat
Kingdom Animalia
Phylum Chordata
Class Mammalia
Order Carnivora
Family Felidae

3. Classification of the domestic cat
Family Felidae
Genus Felis
Species Felis catus, the domestic cat

4. The five kingdom system
Until the mid-twentieth century all living organisms were classified in either the Animal Kingdom or the Plant Kingdom
This led to numerous inconsistencies and absurdities (e.g. bacteria classified as ‘plants’)
Since the 1960s most biologists have recognised five kingdoms: Prokaryota (Monera), Protoctista, Fungi, Plantae and Animalia

5. Kingdom Prokaryota (Monera)
All prokaryotic unicells: cells may form groups or chains, but there is little or no differentiation between them
Include the bacteria, the cyanobacteria and the archaea:
Nostoc
Sulfolobus

6. Kingdom Prokaryota (Monera)
Genetically the bacteria are more different from the archaea than from animals or plants: some biologists propose a three-domain classification, with the Archaea, the Bacteria and the Eukarya having equal ‘domain’ status

7. The three-domain system
The Prokaryota would comprise two of the domains …
the Protoctista contains a wide range of eukaryotes …
with the Plantae, Animalia and Fungi three relatively similar groups.

8. Kingdom Protoctista
As we saw in the previous slide, the Protoctista contains a wide range of very diverse organisms
All are eukaryotic; most are unicellular, and those that are multicellular (e.g. brown or red seaweeds) show very limited cellular differentiation

9. Kingdom Protoctista
‘Animal-like’ Protoctists are often called Protozoa :
Paramecium, a ciliate protozoan
Amoeba, a rhizopod protozoan
Euglena, a flagellate protozoan

10. Kingdom Protoctista ‘Plant-like’ Protoctists are often called Algae :
Chlorella, a ‘green alga’
Assorted dinoflagellates
Assorted phytoplankton

11. Kingdom Fungi
Fungi are eukaryotic heterotrophic organisms with cell walls containing chitin and other polysaccharides as well as cellulose
Typically a fungus consists of a mycelium composed of cylindrical hyphae, which may be multinucleate
Nutrition is always heterotrophic, either saprobiontic or parasitic
Reproduction is by production of sexual or asexual spores

12. Kingdom Fungi False-colour scanning electron micrograph of Penicillium
Green: hyphae, making up the mycelium
Orange: spore-bearing hyphae (conidiophores)
Blue: asexual spores (conidia)

13. Kingdom Fungi
Higher fungi often produce their spores in organised structures called fruiting bodies: these include mushrooms, toadstools, brackets, puffballs etc
Death cap, Amanita phalloides
Shaggy ink cap, Coprinus comatus
Giant puffball, Lycoperdon gigantica

14. Kingdom Plantae Multicellular photoautotrophic eukaryotes
Cell walls contain cellulose
Some cells at least contain chloroplasts (except in some plant parasites like broomrape or dodder, which have lost them)

15. Kingdom Animalia Multicellular heterototrophic eukaryotes
Cells without cell walls
Usually motile, at least at some stage in the life cycle
Nutrition is characteristically holozoic
All except sponges show nervous coordination